As you certainly experienced, Affinity Designer can open FreeHand files, but the result is only usable for the most simple of files. But if you export your file from FreeHand in Adobe Illustrator format, Af Designer can open that and the result is very good. If you can get your hands on a copy of AI CS4 (it stills works under OSX Mojave, while FreeHand only works up to 10.6.8 or under newer versions inside Parallells) you can open FreeHand files directly with AI under Mojave, save as AI file and then open that in Af Designer and the result is very good.